Series system of mercury vapor lighting



Nov. 4, 1958 H. A. VAN DUSEN, JR

SERIES SYSTEM OF MERCURY VAPOR LIGHTING Filed NOV. 2, 1956 3 Sheets-Sheet 1 INVENTOR. H ARoLo A VAN DusEm-R 2W A-rroausY Nov. 4, 1958 H. A. VAN DUSEN, JR 2,359,386

SERIES SYSTEM OF MERCURY VAPOR LIGHTING Filed Nov. 2, 1955 3 Sheets-Sheet 2 \o Fm. 8 HAROLD ANAN Du: sugar INVENTOR.

ATTORNEY Nov. 4, 1958 H. A. VAN DUSEN, JR 2,359,385

SERIES SYSTEM OF MERCURY VAPOR LIGHTING Filed Nov. 2, 1956 3 Sheets-Sheet 3 FFe \0 5 2 W 2 4.3 I i 3 H *QW/Jfl m INVENTOR.

HAROLD ANAN Duseu,Jn.

MAQWW ATTORNEY United States Patent 2,859,386 SERIES SYSTEM OF MERQURY VAPOR LIGHTING Harold A. Van Dusen, Jr., South Milwaukee, Wis., as-

signor to McGraw-Edison Company, a corporation of Delaware Application November 2, 1956, Serial No. 620,002 6 Claims. (Cl. 315-489) This invention relates to a series system of mercury vapor lighting.

In mercury vapor lighting it is sometimes the practice to connect the lights in series, and to provide a constant current "regulator for supplying the system. The characteristics of mercury vapor'lamps are such that a voltage considerably higher than the normal operating voltage is required for a brief instant when the circuit is first energized. Otherwise, the lamps will fail to strike anarc and will thus remain non-operating. Because of this characteristic, it is generally necessary to use an oversize constant current regulator to supply striking voltage to all of the lamps simultaneously for a brief instant at starting. The voltage required thereafter is considerably lower.

This invention is designed to overcome the above noted defects, and objects of this invention are to provide a novel form of series connected mercury vapor system in which very simple means are provided for insuring the'operation of the lamps'at haphazard periods or, at all events, not all at the same time. By this expedient it is possible to utilize a much smaller regulator or constant current transformer, or other device of this type which 'will hereafter be referred to as a regulator.

A further specific object of this invention is to provide a 'novel time delay device which can be positioned between the prongs of a socket of a mercury vapor lamp, and which is so arranged that it will delay the energization of the lamp for a'period of time, and which will thereafter start the lamp operating.

A primary object of this invention is to provide an arrangement such that the successive lamps will not be energized simultaneously, and it is possible, as will appear in the description hereinafter, to provide a very cheap and simple thermostatic device which has a wide tolerance or variation in the time required for it to operate, andin which these defects areutilized so that the thermostatic membersmay be placedin position on each individual lamp socket with assurance that, due to very wide tolerance or variation in manufacture, that they will operate ina haphazard manner, and will, therefore, cause the -successive lamps -to be energized in a haphazard rnanner, so that it is practically impossible for all of'the lamps to start operating at the same time.

ln other words, a further specific object of this invention is to use a very cheap form of thermostaticmember in which the very-defects ofthese relatively cheap members, which are not held to any close tolerance, may be utilized, and these-very defects may be used to produce the'highly desirable'r'esult'thereinabove enumerated.

Afurther object is to provide a construction in which a U-shaped thermostatic member is employed, in which the currentfirst passes through one leg of "this U-shaped member to heat up themember and to cause the opening of a bridging circuit around this lamp after a haphazard time delay, so to speak, and inwhich when the thermostatic-member opens its contacts, the lamp will be placed in themain or series circuit, and which is so arranged that after the lamp has been placed in the series circuit, current will fiow through the lamp and through both legs of the thermostatic member to maintain the member in a heated condition.

A further specific object of this invention is to provide a construction which may be readily applied to existing types of lamp sockets with a minimum of change.

An embodiment of the invention is shown in accompanying drawings in which:

Figure 1 is a diagrammatic view of a portion of the series system.

Figure 2 is a side elevation of a mercury vapor lamp socket showing a portion of the coacting prongs by means of which current is supplied the lamp socket.

Figure 3 is a view looking directly into the lamp socket.

Figure 4 is a view partly in section looking directly at the rear portion of the lamp socket.

Figure 5 is an enlarged view corresponding to Figure 4 with parts broken away.

Figure 6 is a vertical sectional view directly through the lamp socket on the line 6-6 of Figure 5.

Figures 7 and 8 are sectional views on the lines 77 and 8-8 of Figure 5, respectively.

Figure 9 'is a sectional view on the line 99 of Figure 6.

Figure 10 is a sectional view on the line 10-10 of Figure 6, with parts omitted.

Figures 11, 12 and 13 are sectional views on the lines 1111, 12-12 and 1313 of Figure 5, respectively.

I Figure 14 is a perspective view of the bracket which is the main supporting member for the thermostatic unit.

Referring to the drawings, particularly Figure 1, it will be seen that a series system of mercury vapor lighting has been shown diagrammatically. Within such figure it will be seen that the mercury vapor lamps are indicated by the reference character L, and the time delay switches or thermostatic members by the reference character T. In each instance the thermostatic member is connected in parallel or shunt to the corresponding mercury vapor lamp. One of the units or assemblies consisting of the mercury vapor lamp and the thermostatic member or unit, is shown somewhat in detail, and the movable contacts or prongs of the lamp socket are indicated by the reference characters 1 and 2.

The thermostatic unit consists of the U-shaped thermostatic movable member indicated by the reference character 3. This member 3, as will be seen hereinafter, is fastened at the ends of its U-shaped legs or arms to a supporting insulating member. The rounded end or bail portion is provided with a contact 4. The stationary member of this thermostatic unit is indicated by the reference character 5, and is provided with a stationary contact 6.

It is to be noted that the stationary member 5 is connected to the prong 2 of the lamp socket, and one arm of the U-shaped thermostatic movable member 5 is connected to the prong 1. The other arm of the U shaped movable thermostatic member 3 is connected to one side of the lamp L. The other side of the lamp L is connected to the other prong 2. The electric line is indicated by the reference character 7, and it will be seen that this electric line is connected to the prongs 1 and 2 of the lamp socket S when the lamp socket is in operating position, see Figures 2 and 3, as will be hereinafter described. These movable prongs, or movable contacts 1 and 2 of the lamp socket S engage the stationary contacts 8, of the lamp assembly in the usual manner. The prongs 1 and 2 approach each other at their outer ends and a puncturable cutout 9 is interposed between these prongs in the usual manner as shown in Figure 3.

When the thermostatic member is cold it is closed.

This thermostatic unitmay be considered a thermostatic.

cutout or switch having a time delay. When it is closed the contact 4 of the 'movable thermostatic element 3 engages a contact 6 of the stationary element of the unit. When the circuit is first energized each lamp L is shorted by the thermostatic unit associated therewith as is apparent froman examination of Figure 1, Figure 1, however, showing the unit in open position. Under these conditions current passes from one of the prongs, for instance the prong 2 to the member 5, and from thence to the central portion or yolk portion of the member 3 and down one leg to the other prong 1 and back to the line. The heating of the one leg, hereinabove mentioned, of the thermostatic element 3 causes the element to warp downwardly or move downwardly as indicated by the arrow. The hot condition is indicated in Figure 1. Obviously when the member 3 moves downwardly this cutout opens its contact and the lamp is then connected in series. The current now passes through the entire thermostatic element 3 to the other prong 1, and thus the thermostatic element 3 is maintained in a heated condition, and is held open.

When the series circuit is deenergized it is obvious that the thermostatic element 3 cools, and the thermo static cutout closes thus shorting out the lamp L.

As stated, when the circuit is closed the thermostatic element 3 has one leg thereof heated by passage of current therethrough from the prong 2 through the element 5, through one leg of the thermostatic element 3 to the other prong 1. This heats the movable element 3 and it warps or moves downwardly thus opening its contacts and placing the lamp in series as has been described immediately hereinabove.

The thermostatic unit hereinabove described is supported by or, in other words, provided with an insulating body portion 16. This body portion 1% is supported from the lamp socket by means of a bracket 11. This bracket is shown in perspective view in Figure 14. This bracket 11 is connected to the shell 12 of the lamp socket S by means of the screw 13, see Figures 5 and 6. The bracket 11 is connected to one arm of the U-shaped thermostatic element 3. The other arm of the U-shaped thermostatic member 3 is connected to a bracket 14, and from the bracket 14 to the prong 1. The member 5 of the thermostatic unit is connected to a bracket 15, and from there is connected to the prong 2. The prong 2 is also connected to the central contact 16 of the lamp socket.

Other devices could be used in place of the one shown provided they have the time delay feature similar to the one that is set forth in detail hereinabove, and provided they fit directly between the prongs 1 and 2 so as to take up only waste space in the lamps construction, and so as not to protrude or stick out beyond any other portion of the apparatus.

It is desirable to use a permanent magnet such as indicated at 16' which is held clamped in place by means of the bracket 15 hereinbefore described. This permanent magnet will tend to hold the movable member 3 of the thermostatic element in closed position, when it is closed, and will offer a slight resistance to the opening of the thermostatic member. However, when the thermostatic member does open, it opens with a snap action, and therefore, provides a quick break.

Itwill be seen that a simple means has been provided for guarding against the simultaneous operation of all of the lamps at the starting period. Instead of this, the haphazard manner in which the thermostatic elements operate insures a haphazard connecting of each individual lamp in the series circuit. It is very unlikely that more than one or two lamps will ever be put into circuit at the same time. In other words, the very defects of the thermostatic units which occur in manufacture and cause them to operate at uncertain times, that is to say, the tolerance allowed by the manufacturer is utilized in the control of the lamps so it is possible to buy commercial thermostatic units without any particular attention being paid to the time interval that is required for them to open. This is a simple arrangement, is very cheap to make, and is easy to install without any materially great change in the lamp socket structure.

By means of the invention herein described and shown it is possible to use a relatively small constant current transformer or regulator or other device of this nature as only a relatively small maximum voltage is required to insure the successive striking of the different mercury vapor lamps at starting period.

Although this invention has been described in considerable detail, it is to be understood that such description is intended as illustrative and not as limiting as the.

invention is to be interpreted as claimed.

I claim:

1. A series system of mercury vapor lighting comprising a plurality of mercury vapor lamps connected in.

series, a time delay device connected in shunt across each mercury vapor lamp and forming a unit with the lamp which it shunts and being electrically independent of every other time delay device and lamp and each time delay device having normally closed contacts arranged to open when the time delay period has passed, each time delay device having a different period of opening from other time delay devices, whereby the lamps are placed in operative series circuit connection at difiierent intervals of time after the series circuit has been energized.

2. A series system of mercury vapor lighting, comprising a plurality of mercury vapor lamps connected in series circuit, a thermostatic time delay device con-.. nected in shunt across each individual mercury vapor-I.v

lamp and forming a unit with the lamp which it shunts and being electrically independent of every other time delay 'device and lamp, said time delay device having a thermostatic element connected in series in the circuit,

whereby said thermostatic element is heated when the circuit is energized, and the thermostatic element of each of said devices being connected in series with its mercury vapor lamp when such time delay device opens its contacts upon being heated after an interval of time.

3. A series system of mercury vapor lighting comprising a plurality of mercury vapor lamps connected. in series circuit relation, a thermostatic time delay device thermostatic device is kept heated by the current passing in series through the thermostatic device, and its corresponding lamp.

4. A mercury vapor lamp assembly, comprising a 7 socket having a pair of contact prongs projecting therefrom, a mercury vapor lamp mounted within said socket, time delay means carried by said socket and supported therefrom and positioned between said prongs, said time delay device being electrically connected to said prongs 3 and having contacts normally shorting said prongs, and

arranged to open after a time interval.

5. A mercury vapor lamp assembly, comprising a socket having projecting contact prongs located at the rear portion of said socket, a mercury vapor lamp mounted within said socket, and time delay means supported from the rear portion of said socket and positioned between said prongs and electrically connected thereto and having contacts normally electrically connecting said prongs and shorting out said lamp, said time delay device having means for opening its contacts after a time delay, whereby the lamp is directly connected to said prongs and is not bridged or shorted by the contacts of said time delay means.

6. A mercury vapor lamp assembly comprising a socket having projecting contact prongs, a mercury vapor lamp mounted within said socket, a thermostatic time delay device positioned between said prongs and electrically connected thereto and being supported from said socket, said time delay device having a stationary contact and having a U-shaped movable thermostatic member provided with a contact normally engaging the stationary contact, the contacts of said thermostatic time delay device and one arm of said thermostatic member being normally directly bridged across said prongs and shorting out said mercury vapor lamp, said thermostatic member being connected in series with said mercury vapor lamp when said contacts are open, said time delay device being heated by passage of current through one arm thereof at the initial energization of said circuit, and being heated by passage of current through both arms and in series with said lamp during the normal operation of said lamp, whereby said contacts are normally closed when the thermostatic element is cold, and are maintained in open condition when the lamp is in operation.

References Cited in the file of this patent UNITED STATES PATENTS 2,056,619 Reger et al. Oct. 6, 1936- 2,756,382 Wuerth July 24, 1956 

